Phase Coherent
To enable phase coherent operation, all units most share a common sample clock and 1 PPS reference signal.
The common sample clock is derived from the unit designated as primary. The primary unit provides sample clock output to a distribution module (CA1008).
The units designated as secondary receive sample clock from the CA1008 distribution module via their sample clock inputs.
1PPS is input to the CA1008 clock distribution module and is input to the CA7814 via the SMA connector interface. The 1PPS input re-sampled into the CA7814 clock domain and is utilised to ensure the ADC sampling is aligned to the same 1 PPS edge.
Use of a GNSS disciplined oscillator to provide 1PPS and 10 MHz reference signals is common practice, the 10 MHz input is used by the primary CA7814 to ensure long term time/frequency accuracy of the overall system.
High Dynamic Range
Dynamic range effectively determines the Probability of Intercept of weak Signals of Interest (SOI) in the presence of a stronger unwanted signal with a small or large frequency offset. The features embodied within the CA7814 in order to maximise dynamic range are as follows:
Low noise figure. The CA7814 typically sub-10dB noise figure in the 2-30 frequency MHz range.
62 dB RF attenuation range in 2dB steps maintains system linearity even with high input signal levels, meaning the device maintains linearity with a minimum +20 dBm input signal.
Single-tone instantaenous dynamic range exceeds 100 dB.
RF preselection filters which comprise selectable high-pass / low-pass filters provide flexibility in terms of operating bandwidth and interferer rejection.
Low phase noise sample clock minimises blocking.
Full HF Wideband Coverage in Real-time with up to 128 narrowband channels per receiver
The CA7814 is capable of continuously digitising the frequency range 9 kHz – 32 MHz, and is capable of lossless transfer of that data to internal or external DSP resources via high speed digital interfaces.
Systems that don’t instantaneously digitise the entire HF band carry the risk of missing signals of interest – even with fast scan speeds. The CA7814 ensures full HF band capture at all times.
The CA7814 includes a XilinX® ZynQ® System on Chip (SoC) for high performance digital signals processing applications. This enables output of “Power Spectral Density” (PSD) summary frequency domain data with up to 1 million points, providing Operators with an extremely high-fidelity wideband view of emissions across the whole spectrum. The ZynQ also includes a 128 channel channeliser, providing Operators with 128 configurable narrowband DDR/DDC time-domain (narrowband) data channels.